Raman and Fluorescence Spectroscopy of CeO₂, Er₂O₃, Nd₂O₃, Tm₂O₃, Yb₂O₃, La₂O₃, and Tb₄O₇

Abstract

To better understand and ascertain the mechanisms of flotation reagent interaction with rare earth (RE) minerals, it is necessary to determine the physical and chemical properties of the constituent components. Seven rare earth oxides (CeO2, Er2O3, Nd2O3, Tm2O3, Yb2O3, La2O3, and Tb4O7) that cover the rare earth elements (REEs) from light to heavy REEs have been investigated using Raman spectroscopy. Multiple laser sources (wavelengths of 325 nm, 442 nm, 514 nm, and 632.8 nm) for the Raman shift ranges from 100 cm−1to 5000 cm−1of these excitations were used for each individual rare earth oxide. Raman shifts and fluorescence emission have been identified. Theoretical energy levels for Er, Nd, and Yb were used for the interpretation of fluorescence emission. The experimental results showed good agreement with the theoretical calculation for Er2O3and Nd2O3. Additional fluorescence emission was observed with Yb2O3that did not fit the reported energy level diagram. Tb4O7was observed undergoing laser induced changes during examination.

Simultaneous observation of up/down conversion photoluminescence and colossal permittivity properties in (Er+Nb) co-doped TiO2 materials

“…14 Raman spectra of the doped sample show several peaks ranging from 400 to 700 cm À1 , similar to the previous studies. [15][16][17] The result might imply the presence of doped Er 3þ , Nb 5þ ions, and Er 2 O 3 , which is consistent with the XRD patterns.…”

Rare Earth Element Phases in Bauxite Residue

“…Based on the analysis of synthetic and natural cerianite specimens, this band can be attributed to the symmetric breathing mode of Ce-O-Ce bond [67,68]. The band at 396 cm −1 present on the reference spectrum R050379, but missing in current experimental spectrum, is rarely noted in different cerianite Raman spectra [67,68]. The band at 396 cm −1 could also be hidden due to the broadening of 457 cm −1 band.…”

“…The LREE phases were identified by µ-Raman spectroscopy being cerianite (CeO 2 ), following the main band at 457 cm −1 , when comparing with the reference spectrum R050379 from RRUFF database and those spectra given in the literature sources (Figure 1b) [61,67]. Based on the analysis of synthetic and natural cerianite specimens, this band can be attributed to the symmetric breathing mode of Ce-O-Ce bond [67,68]. The band at 396 cm −1 present on the reference spectrum R050379, but missing in current experimental spectrum, is rarely noted in different cerianite Raman spectra [67,68].…”

Vitrification of an intermediate level Magnox sludge waste

“…In HM09-40MS glass (Fig. 4d), an additional peak at 466 cm -1 is observed, which can be assigned to cubic CeO2 crystals [19,20]. In addition, one Raman spectrum taken from HM09-45MS glass (Fig.…”